<style>
    body, html{
        width: 100%;
        height: 90%;
        font-family: Roboto, Arial, sans-serif;
    }
    .Aligner {
        display: flex;
        align-items: center;
        justify-content: center;
        height: 100%;
        width: 100%;
    }

    .Aligner-item {
        max-width: 90%;
        font-size: 2em;
        color: rgba(0,0,0,0.73);
        text-align: center;
    }
</style>
<head>
    <title>Page not found!</title>
</head>
<body>
    <div class="Aligner">
        <div class="Aligner-item">
            Oups, cannot find this page!
        </div>
    </div>
</body>
